台湾海峡沙蚕科一新种

A NEW SPECIES OF NEREIDAE (POLYCHAETA) FROM TAIWAN STRAIT

本文根据台湾海峡西部海域调查中采集的标本进行鉴定研究,发现了沙蚕科全刺沙蚕属一新种。文中附图并详细地描述了其形态特征,同时与其近似种作了比较。

A new species of Nereidae was found in waters 16-40 meters deep in the comprehensive survey of the Taiwan Strait in April,1984.The new species is named as Nectoneanthes fujianensis.The specimens is deposited in the Third Institute of Oceanography,State Oceanic Administration,Xiamen.The description of the new spocies is as follows:One complete specimen measures 55 mm in length and 3.2 mm in width and consists of 100 segments.The pros tomium is subtriangular.There are two pairs of eyes on the posterior Of the prostomium.The posterior eyes are larger than the frontal ones,in trapezoidal arrangement.The palpi are small,with Pointed ends.Two antennae are fat and large.The longest one of the peristomial cirri extends backward to the setiger 5(Fig.1).The proboscis has conical horny paragnaths on the oral and maxillar rings.Ⅰhas one cone,Ⅱhas 11-16 cones in two oblique rows,Ⅲhas one cone,Ⅳhas 13-14 cones in two arcs,Ⅴhas no cone,Ⅵhas 8-12 cones in a cluster andⅦandⅧhave a lot of teeth arranged in two rows,one row is near the maxillar ring with 35 45 teeth in various size.The maxillary is yellow with coarse lateral denticulations(Fig.2).The first two pairs of parapodia are subbiramous and the following parapodia are biramous.All the dorsal cirri,ventral cirri and notoseta lobes and ventral lobes are digited on the anterior body(Fig.3).From setiger 14,the supronotoligula is inflated and divided into two lobes.Between the two lobes,the dorsal cirri are located.All the setae in the notosetal and ventral lobes are homogomph spinigerous except a few which are slightly heterogomph spinigerous in the ventral lobes.Nectoncanthes was built by Imajima in 1972 when there were only two species,and later,a new species was found by Wu Baoling who combined Nereis alatopalpis(Wesenberg-Lund,1949)into Nectoneanthes.So far,there are four species in this genus.Nectoneathes fujinaensis is very similar to N.multignatha and N.oxypoda.The differences lie in the features of the prostomium and the paragnaths of proboscis.In this new species,Ⅲhas only one coae andⅤhas no cone at all.